In a 4-liter three-necked flask equipped with a stirrer, thermometer and reflux
condenser, 101 g (1 mole) of triazolidine-3,5-dione, 2775 g (30 moles) of
epichlorohydrin and 2 ml of triethylamine are heated to 80°C by means of an
oil bath. The mixture reacts exothermically so that the oil bath may be
removed. After the exothermic reaction has abated, the reaction mixture is
stirred at 80°C. The total reaction time is 10 hours. 250 g of 50% sodium
hydroxide solution are added dropwise to the solution obtained over a period
of 4 hours at from 30 to 40°C in such a way that the water added and the
water formed during the reaction is continuously removed by azeotropic distillation at from 30 to 60 Torr using a water separator. To complete the
reaction, the reaction mixture is stirred for another hour and the sodium
chloride formed is separated by filtration. The sodium chloride is washed twice
with 200 g of epichlorohydrin and the combined epichlorohydrin solutions are
washed with 200 ml of water. After the organic phase has been dried over
sodium sulfate, the solvent is removed by concentration in a rotary evaporator
and the residue is dried, ultimately at 80°C/0.2 mbar, to constant weight. 240
g of a light brown viscous oil are obtained. It was found to have an epoxide
value of 0.93 and has a chlorine content of 2.75%. The viscous oil crystallizes
after standing for from a few hours to days. The practically pure 1,2,4-
triglycidyl triazolidine-3,5-dione melting at from 98° to 103°C crystallizes by
dissolution in methanol and cooling to 5°C. IR- and NMR-spectra in
conjunction with elemental analysis and epoxide determination confirm the
assumed structure. Melting point 94-96°C.
